Types of an OED include an organic light emitting device (OLED), an organic photovoltaic cell, an organic photo conductor (OPC), or an organic transistor.
Since the OED includes an organic layer vulnerable to an external factor such as water, structures capable of preventing permeation of an external material are disclosed, for example, in the patent documents 1 to 4.
Particularly, unlike a structure using a glass substrate having an excellent barrier property as a substrate, in a flexible structure using a polymer film as a substrate, prevention of the permeation of such an external material is a more important issue.
Accordingly, in the flexible structure, a process of forming a barrier layer on an entire surface of a device during the manufacture of the device may be required.
However, even when the barrier layer is formed on the entire surface, it is necessary to expose a pad region connected to an external circuit. Accordingly, while it is considered that a mask is used to form the barrier layer for exposure, the number of processes is increased, and therefore it is difficult to form a uniform barrier layer. Particularly, when atomic layer deposition (ALD) is applied as a method of forming a barrier layer having an excellent barrier property, it is not easy to apply a masking process due to the characteristics of the process. Alternatively, a process of adhering a pressure-sensitive adhesive sheet to the pad region before forming the barrier layer, and removing the pressure-sensitive adhesive sheet after forming the barrier layer may be considered (for example, refer to Reference 6).
However, according to the process, there is a very high probability to generate contamination of a pad region by the pressure-sensitive adhesive sheet, and therefore performance of a device is considerably degraded.